calling subclass method does not pass the obj only the argument

I have these classes

 classdef LUS < handle
  methods 
   function fun1(obj,extravalues)
    %some code using extravalues
   end
  end
 end

and:

 classdef FLUS < LUS
  methods
   function fun1(obj,extravalues)
     fun1@LUS(obj, extravalues);
       %some extra code using extravalues
   end
  end
 end

however when I run

 OBJ=FLUS;
 OBJ.fun1(extravalues);

then as "fun1" of "LUS" is executed nargin is only 1. Meaning that obj="extravalues" and extravalues is undefined...

How should I call fun1@LUS(obj, extravalues) so that "obj" is passed as "obj" and "extravalues" is passed as "extravalues"?

[Honglei Chen]

I'm not sure I understand the question, this should be automatically taken care of by MATLAB. Do you have an error message? Could you elaborate more?

[Adam]

This seems to do exactly what it should do when I try it.

[Steven Lord]

That's not the behavior I see in release R2017b. Here are my versions of your class definitions, with a few lines added to display some diagnostic information.

>> type LUS.m

   classdef LUS < handle
    methods 
     function fun1(obj,extravalues)
      %some code using extravalues
      disp('Inside fun1 in LUS')
      whos
      nargin
     end
    end
   end

>> type FLUS.m

   classdef FLUS < LUS
    methods
     function fun1(obj,extravalues)
         disp('Inside fun1 in FLUS')
         whos
         nargin
       fun1@LUS(obj, extravalues);
         %some extra code using extravalues
     end
    end
   end

Here's how I used those classes.

>> OBJ=FLUS;
>> extravalues = 1:10;
>> OBJ.fun1(extravalues);
Inside fun1 in FLUS
  Name             Size            Bytes  Class     Attributes

    extravalues      1x10               80  double              
    obj              1x1                 8  FLUS                

ans =

       2

Inside fun1 in LUS
  Name             Size            Bytes  Class     Attributes

    extravalues      1x10               80  double              
    obj              1x1                 8  FLUS                

ans =

       2

As you can see, the superclass method received both the inputs with which the subclass method called it. You didn't mention what you used for extravalues, so I chose a simple double array.

[Adam]

Personally, when doing this I favour the option of not over-riding the base class function and instead having a setup as:

classdef LUS < handle
   methods 
      function fun1(obj,extravalues)
         % Do some common base class stuff
         doFun1( obj, extravalues )
      end
   end

    methods( Access = protected )
       function doFun1( obj, extravalues )
       end
    end
end

and in the subclass:

classdef FLUS < LUS
   methods( Access = protected )
     function doFun1(obj,extravalues)
         %some extra code using extravalues
     end
   end
end

There are also variations on that that I use, depending if the subclass should always add something (in which case make the function abstract in the super class) or if it should be pre- or post- what the base class does.

It is mostly just a question of taste though. Your version should work from what I see.

Answer 1

[Micke Malmström]

This seems to work:

 OBJ=FLUS;
 OBJ.fun1(OBJ,extravalues);